It's All About Chemistry

[Heathcliff]

Cosmetics Chemistry: Beauty Ingredients and Their Purposes



Although trying to figure out what goes into your favorite eye shadow or shampoo can feel like trying to translate a language you’ve never heard before, each ingredient on the list—from aqua to zinc—really does have a purpose and function.

Agar, also known as algae, carageenan, laminaria, ulva lactuca, and ascophyllum, contains protein and several vitamins. It’s usually added to moisturizers as an emollient or antioxidant.

Alcohol SD-40 is a high-grade cosmetic alcohol that acts as an emollient and a vehicle for the other ingredients. Alcohols (including ethyl alcohol, methyl alcohol, and benzyl alcohol) also help keep the product bacteria-free, but some alcohols can cause dryness and irritation for those with sensitive skin.

Allantoin is used in skin creams and lotions and is a by-product of uric acid; it is an effective calming agent that also reduces skin irritation.

Aluminum chlorohydrate is one of the most common ingredients in antiperspirant. Technically it’s a salt, and when it reacts with the enzymes in sweat, it forms a temporary “plug” that sits in the pore and prevents more sweat from being released. (The plug is easily washed or sloughed away by bathing.)

 Aluminum chlorohydrate also acts as an astringent, causing the pores in the underarm to constrict so they can’t release more sweat.
Cellulose can refer to any plant-derived matter. In creams and lotions, it is used as a thickener and allows oil ingredients to blend with water without separating.

Diethanolomine, like its cousin triethanolomine, sometimes goes by its initials DEA (or TEA, in the case of triethanolomine). It’s a solvent that’s added to cleansers to make them lather and foam.

Dimethicone is a form of silicone. Used often in hair products, it makes the product slippery and spreadable. In general, any ingredients with the suffix “cone” are forms of silicone that perform similar functions.

Glycerin is found naturally in skin and is added to skin creams to increase hydration.
Glycol stearate is a thickener added to products like shampoos to give them a pearly or opalescent look. It doesn’t change how the product works, but it makes it look appealing.

Lanolin is a protein derived from sheep’s sweat glands. It’s a high-quality moisturizer that’s especially effective for people with dry or sensitive skin. Chemically, it’s very similar to oil produced by human sebaceous glands.

Lecithin, a lipid found naturally in plant and animal cells, is used in moisturizers and skin creams as an emollient and moisturizing agent. It helps protect the outer layers of the epidermis against dryness and irritation, keeping the layers soft and allowing them to repair and regenerate.
Mica is a reflective mineral that’s used in makeup products and sometimes toothpaste. It is responsible for shimmer and pearlescence.

Panthenol, sometimes called pantothenic acid, is a form of vitamin B5. In hair products, it seals the hair shaft, making strands soft and shiny. It’s sometimes used in skin ointments that treat burns or irritation because it can reduce inflammation and speed healing.

Parabens (including butylparaben, methylparaben, etc.) are preservatives. Used widely in up to 70 percent of makeup, skin products, and other cosmetics, they prevent spoilage and inhibit bacteria and fungi.

Potassium sorbate inhibits the growth of mold and yeast, and is often used as a preservative.

Propylene glycol, like other glycols, is a humectant agent used in skin creams that also helps other ingredients be absorbed more readily. It is not dangerous, as many chain emails or alarmist websites would have you believe. In cosmetics, it is used in very small amounts, and the Department of Health and Human Services has determined that it poses no threat.

Sodium hydroxide is the chemical term for lye. This alkaline substance is used to modify a product’s pH balance (i.e., to make it less acidic). Products with large amounts of sodium hydroxide can severely irritate skin.

Sodium lauryl sulfate is a surface-active substance used most often in shampoo, but it is also used in skin cleansers. It loosens dirt and oils, making it easier to wash them away. Sodium lauryl sulfate is highly irritating to skin (its cousin sodium laureth sulfate is milder), but contrary to popular belief, it does not cause cancer.

Stearyl alcohol is used in emulsions to keep all the ingredients mixed together and suspended properly. It is also an emollient.
Talc is one of the primary ingredients in powdered cosmetics like eye shadow and blush. It is an absorbent natural compound that comprises silicon and magnesium.

Titanium dioxide is used to thicken and lighten cosmetics like foundation, blush, and eye shadow. It’s also a sunscreen, protecting against both UVA and UVB rays without causing irritation to skin.

Tocopherol, along with its chemical cousins tocopherol acetate, tocopheryl linoleate, and tocopheryl nicotinate, is a form of vitamin E. It is added to lipsticks and other emollient cosmetics like concealer or cream blush as an inexpensive but powerful antioxidant.

Xanthan gum is a thickening agent that gives products their proper texture.

This is far from an exhaustive list; there are literally thousands of ingredients that can be included in modern cosmetics. Most products contain active ingredients, plant extracts, preservatives, thickeners, emollients, emulsifiers, and also a few fragrance additives and coloring agents. One way to tell the proportion of these ingredients to one another is to see where they fall on the product’s label; the active ingredients and those that exist in large amounts are listed first, and fragrances, dyes, and ingredients that exist only in tiny amounts are listed at the end. Reading cosmetics labels can still feel like deciphering a foreign language, but being able to translate even a few key words and phrases makes everything make a lot more sense.

~credits to the source

[lovemarie]

. . . . . . . . . . . . .

[jamesbond]

Fire Science Experiment - Let's learn about an important science concept of fire







Exploding fire science experiments are wonderful features at live science museum shows. These experiments "wow" the crowd and help to show something about science, but they are not safe unless the building is set up correctly. This fire science experiment is not exploding, but is great for teaching us about the science of fire.

Materials Needed

Clear glass jar
Antacid tablets (must contain sodium bicarbonate)
Disposable cup
Water
Table knife or fork
Candle
Matches
Small piece of wax-based clay
Tongs

Step 1: Remove the label and completely dry the inside of a clear glass jar. A spaghetti sauce jar works well.

Step 2: *An adult must handle the antacid tablets or an adult must provide close supervision while the kids help with the antacid tablets.* Take an antacid tablet out the package and place it in the bottom of a dry cup. Using the table knife or fork, chop up the antacid tablet into smaller pieces.


Using the table knife or fork, break the antacid tablets into smaller pieces in the bottom of a dry cup.

Step 3: Place a ball of clay on the bottom of the candle. Now press the unlit candle and clay into the bottom of the jar, inside the jar. Using tongs or long needle-nose pliers helps to grip the candle to press it against the glass at the bottom of the jar.

Step 4: Pour the broken antacid tablet pieces around the unlit candle.


Antacid pieces in the bottom of the jar surrounding the candle

Step 5: *An adult must handle lighting the candle.* Light the candle by turning the jar upside down. The flame from the match rises which is why holding the jar upside down helps allow the candle to be lit inside the jar. Turn the jar over and set it on the counter.


Have an adult carefully light the candle

Step 6: Tip the jar slightly and carefully pour the water in the jar around the candle, without pouring it over the flame.


Quickly, but carefully pour the water around the lit candle, but do not extinguish the flame

Step 7: Observe the reaction taking place within the mixture of water and tablet pieces.


The sodium bicarbonate reacts with water resulting in CO2 gas. The bubbles in the jar is the result of CO2 gas being produced.

Step 8: Watch the candle for the next minute or two. The candle will start to CRACKLE, then eventually burn out.


As C02 gas is produced from the chemical reaction, other gases inside the jar are pushed out.


SCIENCE LEARNED

The bubbles you saw as soon as the water was added to the antacid pieces was carbon dioxide gas being released. Antacid contains sodium bicarbonate (NaHCO3), which is also known as baking soda. Sodium bicarbonate is a weak base. When antacid is combined with water it reacts quickly, resulting in the release of sodium, water and carbon dioxide. Using smashed up pieces of the antacid helps speed up the reaction.

The second interesting thing that happened in this experiment was what happened to the fire. The lit candle in this experiment was using oxygen to continue to burn. When the carbon dioxide is released it starts to mix with the oxygen-rich air in the jar. Carbon dioxide gas is heavier than oxygen but this is not why the flame is extinguished. As more and more carbon dioxide gas is released by the antacid reaction there just is not enough oxygen left in the jar for the fire to continue. At first, the flame may CRACKLE, but then finally it will stop burning.

Did you know that there are carbon dioxide fire extinguishers? CO2 (carbon dioxide) fire extinguishers work by moving the oxygen away from the location of the fire, extinguishing the flames. Now that we have seen the results of the fire experiment we know why these types of fire extinguishers work well.

[lovemarie]

. . . . . . . . . . .

[jamesbond]

. . . . . . . . . . . . . . . .

[jamesbond]

. . . . . . . . . . .

[lovemarie]

. . . . . . . . . . . .

[Heathcliff]

Albert Szent-Györgyi's Discovery of Vitamin C



Vitamin C and the Body


Vitamin C enables the body to efficiently use carbohydrates, fats, and protein. Because vitamin C acts as an antioxidant — a nutrient that chemically binds and neutralizes the tissue-damaging effects of substances known as free radicals — it is vital to the growth and health of bones, teeth, gums, ligaments, and blood vessels. Vitamin C also plays a key role in the formation of collagen, the body’s major building protein, and is therefore essential to the proper functioning of all internal organs.

Vitamin C is found in various foods, including citrus fruits such as oranges, lemons, and grapefruit; in green vegetables such as spinach, broccoli, and cabbage; and in tomatoes and potatoes. Food processing may degrade or destroy vitamin C, as can exposure to air, drying, salting, cooking (especially in copper pots), or processing. (Freezing does not usually cause loss of vitamin C unless foods are stored for a very long time.)

In modern times, access to fresh fruits and vegetables is common, rendering full-blown cases of vitamin C deficiency relatively rare. Cases are normally limited to isolated elderly adults, usually men whose diet is limited to foods lacking in vitamin C, as well as to infants fed reconstituted milk or milk substitutes without a vitamin C or orange juice supplement. Those with certain illnesses, such as AIDS, cancer or tuberculosis, surgical patients, and those exposed to long periods of cold temperatures can also suffer from vitamin C insufficiency.

The Discovery of Ascorbic Acid


In 1930, Szent-Györgyi returned to Hungary, accepting a post as professor of medicinal chemistry at the University of Szeged. There he showed his sample of hexuronic acid to J. L. Svirbely, an American-born chemist of Hungarian descent, who had previously worked with Charles King, a vitamin researcher at the University of Pittsburgh. Svirbely, working with Szent-Györgyi, conducted a landmark experiment on guinea pigs, which, like humans, must ingest vitamin C to maintain health since it cannot be produced within their bodies.

Svirbely divided the animals into two groups: one that received boiled food (boiling destroys vitamin C) and the other that was fed food enriched with hexuronic acid. The latter group flourished, while the first aggregation of guinea pigs developed scurvy-like symptoms and died. Svirbely and Szent-Györgyi decided hexuronic acid — renamed ascorbic acid to reflect its anti-scurvy properties — was indeed the long sought vitamin C. In 1933, Szent-Györgyi set about to find additional, natural sources of ascorbic acid for further study.

Although orange juice and lemon juice have high levels of ascorbic acid, they contain sugars that make purification extremely difficult. Szent-Györgyi solved the problem by making imaginative use of the local specialty, paprika. Szeged is the paprika capital of the world, where matching salt and paprika shakers are found on every restaurant table. One night, Szent-Györgyi recalled, his wife served him fresh red paprika for supper. As he wrote in his autobiography, “I did not feel like eating it so I thought of a way out. Suddenly it occurred to me that this is the one plant I had never tested. I took it to the laboratory ... [and by] about midnight I knew that it was a treasure chest full of vitamin C.”

Within several weeks Szent-Györgyi had produced three pounds of pure crystalline ascorbic acid, enough to show — when fed to the vitamin C-deficient guinea pigs — that the acid was equivalent to vitamin C.


Szent-Györgyi’s Nobel and Later Research
Just four years after the ascorbic acid discovery, Szent-Györgyi received the Nobel Prize for his seminal work. That year, in 1937, the deliberations in the Nobel Committee centered on whether the Prize should go to Szent-Györgyi alone or be shared with several other scientists who had conducted similar work. In the end, the Prize was given to Szent-Györgyi alone, but the deliberations were reportedly long and acrimonious.

Szent-Györgyi went on to identify and study actin and myosin, proteins responsible for muscle contraction, and demonstrated that the compound adenosine triphosphate (ATP) is the immediate source of energy necessary for muscle contraction. He later carried out additional studies of citrus fruits, identifying flavonoids and postulating its function as strengthening capillary blood vessels.

Szent-Györgyi then turned to the study of organic compounds known to play a part in the breakdown of carbohydrates to carbon dioxide, water, and other substances necessary for the production of usable energy by the cell. His work laid the foundation for Sir Hans Krebs' explanation of what later would be known as the Krebs cycle: the three-stage process by which living cells break down organic molecules in the presence of oxygen to harvest the energy required for growth and division.

In 1947, Szent-Györgyi immigrated to the United States, where he assumed the directorship of the Institute for Muscle Research in Woods Hole, Massachusetts. There he investigated the causes of cell division and the root causes of cancer. He was an accomplished and prolific author, producing among other works “The Crazy Ape” (1970), a passionate commentary on science and the prospects for human survival on Earth. Albert Szent-Györgyi died on October 22, 1986.


~credits to the source

[lovemarie]

 . . . . . . . . . . . . .

[jamesbond]

. . . . . . . . . . . .

[lovemarie]

. . . . . . . . . . . .

[dabski]

Wow. Itaas ang kamay ng mga chemist dito. pati na rin chem eng'g.

[lovemarie]

. . . . . . . . . . . . . . . .

[jamesbond]

more 'chemistry' finds . . . . . .

[carlo1225]

malawak talaga itong Chemistry...at nakaka nose bleed kung uunawain... 

share lang din ako...
Chemical Reactions...